Relief under Paragraph 9 of Schedule 4 is available only on the making of a claim. The time limit for such a claim is: within two years of the end of the year of assessment in which the disposal is made (or the gain is treated as accruing) or within such further time as the Board may allow.
Each claim is to be supported by such particulars as are required for the purposes of establishing
•entitlement to relief, and
•the amount of the relief due.
Thus the onus of proving the claim is placed on the company. HMRC will not be able to assist in identifying gains that were deferred so long ago.